Make DAL sensitivity level removal graceful

It does not error out if it does not exist like with other
resources.
This makes it more consistent and easier to work with in tests.

pkg/dal/service.go

@@ -189,7 +189,7 @@ func (svc *service) RemoveSensitivityLevel(levelIDs ...uint64) (err error) {
 		log := log.With(zap.Uint64("ID", l.ID))
 		if !nx.includes(l.ID) {
 			log.Debug("sensitivity level not found")
-			return errSensitivityLevelRemoveNotFound(l.ID)
+			continue
 		}
 	}